The Study On Caragana Protein Extraction

Caragana was a kind of important plant resources when the ecology and environment were constructed in our arid areas. As the large planting areas and its own growth characteristics that they should be flat crop, a large number of protein-rich caragana branches were produced. Based on the nutritional content analysis of the branches of Caragana, summer flat crop branches of Caragana were selected as the raw materials. Under the optimized alkaline extraction process, the effect on alkaline extraction when the raw materials were pretreated via extrusion and cooking was researched. Caragana protein isoelectric point was determined, and the bleaching influences of caragana protein on the type and amount of bleaching agent were examined. Furthermore, protein extraction process has an impact on caragana protein through SDS-PAGE electrophoresis and discussing the changes in nutrients. Accordingly, a new caragana protein extraction process was designed. Production line design, equipment selection and transformation were studied. Full-wavelength scan verification was made in order to achieve the purpose of making full use of caragana resources.Via optimizing alkaline extraction caragana protein process, optimal conditions were identified as:solid-liquid ratio 1:20, extraction time 60 min, NaOH concentration 0.1 mol/L, extraction temperature 130℃. By orthogonal test to determine the optimal conditions for extrusion cooking pretreatment of raw materials: barrel temperature 130℃, moisture content of materials 30%, screw speed 160 r/min. Screw speed has a significant effect on caragana protein extraction, and extrusion cooking could largely increase extraction rate of caragana protein. Caragana protein isoelectric point was 4.0. Ethanol as a bleaching agent and raw materials (1:1 m/V) were freeze-dried after washing and bleaching, excellent caragana protein separation products were obtained. In the experiment, the yield on extraction and separation of protein dry matter was 24.03%, protein extraction rate was 65.39%. Protein subunits were located in 58.8 kDa、40.7 kDa、37.3 kDa、34.5 kDa、32.2 kDa、29.2 kDa、21 kDa and 19.4 kDa. Alkaline extraction process could change caragana protein structure, and extrusion cooking pretreatment of raw materials might lead to structural changes. By designing a production line with daily treatment of caragana branches (12t), the daily production of separating protein was about 4 t. The processes was determined as:coarse crushing�'premixing �'xtrusion cooking�'mixed extraction�' solid-liquid separation�'coagulation and sedimentation�'protein separation�'bleaching�' drying�'package. A new two-way screw and twin screw extrusion cooking machine and three counter bleaching tower were designed.